diff --git a/2201/220102-CN.cpp b/2201/220102-CN.cpp
new file mode 100644
index 0000000..e4d3225
--- /dev/null
+++ b/2201/220102-CN.cpp
@@ -0,0 +1,18 @@
+#include <iostream>
+
+class Solution {
+public:
+	// O(log(n))
+	static int lastRemaining(int n) {
+		int cnt = 0, ret = 1;
+		for (int i = n; i >>= 1; ++cnt);
+		for (int i = 0; i < cnt; ++i, n >>= 1)
+			ret += !(1 & i) || (1 & n) ? (1 << i) : 0;
+		return ret;
+	}
+};
+
+int main() {
+	std::printf("%d\n", Solution::lastRemaining(1));
+	return 0;
+}
diff --git a/2201/CMakeLists.txt b/2201/CMakeLists.txt
index b367a11..20e68cc 100644
--- a/2201/CMakeLists.txt
+++ b/2201/CMakeLists.txt
@@ -3,4 +3,4 @@ PROJECT(2201)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2201 220101.cpp)
\ No newline at end of file
+ADD_EXECUTABLE(2201 220102-CN.cpp)
\ No newline at end of file